Really enjoyed it! Rating it as a demo, not as the full game. There are some obvious things to add in the future, such as a use for money, a save function, make it so your "suspicion" can't go into the negatives. However I'd love to mention a few other functions that would be fun:
Add in a gallery: so that when you win, or even if you lose, you can look at all the pics you've unlocked over time.
Dialogue with the teachers beyond just the "compliments" option: probably something before doing it for the first time as a one time conversation, and then dialogue/narrative DURING the sex act that would be repeated.
Something more functional to grind the "attend class" function. To actually lower your suspicion enough to make a difference, you have to attend class so many times and it gets tiring to put your mouse all over the screen, clicking and clicking and clicking and clicking. Maybe instead of going to a separate screen when you click "attend class", it just takes up the class period and reduces your suspicion, and you can just click it over and over again like that.
Maybe instead of the suspicion being for YOU getting expelled, it's suspicion on the teachers, each one gets an individual "suspicion" score, and if they reach 100, that teachers is discovered, and fired. But, as in real life, YOU probably wouldn't suffer many consequences, if any (due to being a minor). I just thought it might be a nice touch, and make things a bit more interesting. Time spent away from one of the teachers could reduce their individual suspicion.
These are just a few suggestions, I have more, and if you need help writing dialogue like I mentioned up there, I'd love to help!